The natural resistance against the majority of potential pathogens that exist in most plant species is known as non-host resistance. Several reports suggest the role of antioxidant enzymes in non-host resistance. We assayed the expression or activity of four scavenging enzymes during non-host pathogen-plant interaction (Xanthomonas hortorum pv. pelargonii/mung bean) and host pathogen-plant inte...

Table grape (Vitis vinifera L.) quality includes the condition of both the berries and the rachis. In the present report, physiological parameters of Red Globe rachises from fully elongated inflorescences (RFEI) and from mature clusters were studied after storage at 0 or 20 °C for different durations. To understand changes in rachis physiology as a result of changes in temperature conditions an...

Metals and polycyclic aromatic hydrocarbons (PAHs) are known to be toxic to plants. Because metals and PAHs often are cocontaminants in the environment, plants can be subjected to damage caused by their combined effects. We recently found that copper and an oxygenated PAH (1,2-dihydroxyanthraquinone [1,2-dhATQ]) synergistically are toxic to plants. This synergistic toxicity was linked indirectl...

Herbicides adversely affect both the target plant and its environment. In this study, Helianthus annuus L. cv. “Oliva CL” was treated post-emergence with 0.3 to 3.1 mM quizalofop-p-ethyl. The peroxidase activity (POD), ascorbate peroxidase activity (APX), lipid peroxidation, pigment system and total phenolic content were then determined on the 1st, 5th, 10th and 15th days following treatment. T...

Curtis, Kathleen S., Wan Huang, Alan F. Sved, Joseph G. Verbalis, and Edward M. Stricker. Impaired osmoregulatory responses in rats with area postrema lesions. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R209–R219, 1999.—Area postrema lesions (APX) in adult male rats produced a robust spontaneous intake of 0.5 M NaCl, as reported previously. The largest NaCl intakes (up to 1...

A greenhouse pot experiment was conducted to study the impact of arbuscular mycorrhizal fungi--Glomus versiforme (Gv) and Rhizophagus intraradices (Ri) on the growth, Cd uptake, antioxidant indices [glutathione reductase (GR), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), ascorbate (ASA), glutathione (GSH) and malonaldehyde (MDA)] and phytochelatins (PCs) production of...

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this...

We consider the problem of preemptively scheduling a set of n jobs on m (identical, uniformly related, or unrelated) parallel machines. The scheduler may reject a subset of the jobs and thereby incur jobdependent penalties for each rejected job, and he must construct a schedule for the remaining jobs so as to optimize the preemptive makespan on the m machines plus the sum of the penalties of th...

We provide new non-approximability results for the restrictions of the Min Vertex Cover problem to bounded-degree, sparse and dense graphs. We show that for a suuciently large B, the recent 16/15 lower bound proved by Bellare et al. 5] extends with negligible loss to graphs with bounded degree B. Then, we consider sparse graphs with no dense components (i.e. everywhere sparse graphs), and we sh...

The Steiner tree problem asks for a shortest subgraph connecting a given set of terminals in a graph. It is known to be APX-complete, which means that no polynomial time approximation scheme can exist for this problem, unless P=NP. Currently, the best approximation algorithm for the Steiner tree problem has a performance ratio of + , , whereas the corresponding lower bound is smaller than + , ....